I have sworn by Allaah The Great to give all my property in charity for the Sake of Allaah. Is this regarded as a vow? What are the effects and consequences in case of not fulfilling the oath?
May Allaah Reward you.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

The statement in question is an oath which, in case of being broken by the swearer, could be expiated like other oaths. It is permissible for you, dear questioner, to break your oath and give nothing of your property in charity. But in this case, due on you is an oath expiation, in response to the Statement of Allaah The Almighty (which means): {Allaah Will not Impose blame upon you for what is meaningless in your oaths, but He Will Impose blame upon you for [breaking] what you intended of oaths. So its expiation is the feeding of ten needy people from the average of that which you feed your [own] families or clothing them or the freeing of a slave. But whoever cannot find [or afford it] – then a fast of three days [is required]. That is the expiation for oaths when you have sworn.} [Quran 5:89]

Let us here evoke the questioner’s mind to the fact that he should not be hasty in swearing by Allaah The Almighty because failing to fulfill the oath puts one in difficulty. Moreover, taking many oaths may lead him to not exalt The Great Lord. That is why Allaah The Almighty Says (what means): {But guard your oaths.} [Quran 5:89]

Allaah Knows best.